Blasting-cap



(No Model.)

J. R. FRANCE.

BLASTING GAP.

No. 356,064. Patented Jan. 11, 1887.

lflmrnn STATES A'rnNT Prion.

JOSEPH It. FRANCE, OFv NEIV YORK, N. Y., ASSIGNOR T THE METALLIC CAP M ANUF ACTURIN G COMPANY,

BLASTlN OF ENFIELD, CONNECTICUT.

G CAP.

SPECIFICATION forming part of Letters Patent No. 356,064, dated January 11, 1887.

(No model.)

To all whom it may concern.-

Be it known that I, JOSEPH It. FRANCE, a. citizen of the United States, residing at New Yorlqin the county of New York and State of New York, have invented new and useful Improvements in BlastingC-aps, of which the following is a specification. I

My invention relates to the manufacture of blasting'caps for exploding powder, dynamite, [O nitro-glycerine, gelatine-powder, and othcrexplosives.

It is the purpose of my invention to provide acap for blasting purposes of increased power and elficiency, composed of a compressed body 1 of gun-cotton primed with fulminate of mercury, or a mixture ofsnch fulminate with other explosives or chemicals, or other substances which shall be capable of exploding high or low grade powder.

My invention consists in the novel features of construction and combinations of parts hereinafter set forth, and definitely pointed out in the claims following this'specification.

In the accompanying drawings, Figure 1 is a 2 perspective view of the compressed body of gun-cotton of which the cap is formed. Fig. 2 is acent-ral vertical section of the compressed body placed in the copper shell and primed to form the cap. Fig. 3 is a vertical section show- 0 ing the same invention with the priming differently applied.

Hitherto caps of the class to which this invention belongs havebeen made usually of fulmi-nate of mercury or a mixture of such,

5 fulminate with chlorate of potash, in varying proportions, while in other casesgun-cotton of alow grade has been reduced to a fine impalpable powder by chemical means and then nitrated, giving as a result a gun-cotton of low 0 grade, which in some cases has been chlorinated and mixed with chlorate of potash and then with fulminate of mercury in various proportions. In some cases, also, the gun-cotton has been first reduced to a dust by mechanical means, then nitratedand mingled with the chlorate of potash and fulminate. cases the gun-cotton was of high grade and much more effective in use. In these forms of cap the gun-cotton does not act fully as a detonator; but its inert power being enhanced by the quick action of the fulminate,it will in somecases operate as an cxploder for certain grades of powder.

It is well known that a high grade of gun: cotton is increased in eificicncy by being corn 5; pressed; but to apply the requisite degree of compression to the compounds mentioned above is an extremely dangerous operation, bcsides impairing the efficiency of the fulminate of mercury, which is deteriorated by being subjected to a considerable compression.

To avoid these objections and secure the beneficial results proposed by my invention, I take gun-cotton of a. high grade and compress it into cylindrical body 1 (see Fig. 3) under a pressure ofahout four thousand pounds to the square inch. This body is then inserted within a suitable copper shell, 2, of proper caliber, and is primed by pressing upon it fulininate of mercury, or such fulminate mingled with chlorate of potash or other chemical, l'orminga priming, 3. For aten-grain cap of this sort I use about seven grains of gun-cotton and two and one-halfgrains of fulminate of mercury mingled with half agrain of chlorate ofpotash. Such acap, made in the manner set fortlnwill explode low or high grade powder; but the proportions given above may be changed withoutdeparting from myinvention.

I propose to form the body of compressed 3 gun-cotton with arecess or opening, 4, of conical or other form, as shown in Figs. 1 and 2. This may be effected by'any suitable form of plunger-press, in which the compressed body 1 may be simultaneously formed. This body, being placed'in the shell 2, ispri med by pressing into t-herecess or chamber4 the fulminate of mercury, or such fulminate mingled with chlorate of potash or other substances.

The priming 5, Fig 2, is preferably placed into the opening 4by a plunger having asmall central nipple upon its end, by which acentral conical depression, 6, is formed in the priming. The form of this depression may, however, be modified and its depth and diameter varied according to circumstances. In these i The recess 4*may be made of any depth. I have shown it in Figs. 1 and 2 as extending nearly to the bottom of the body; but it may be of any less depth,or it may extend entirely to the bottom of the body.

By forming the opening or recess 4 to receive the priming the action of the gun-cotton is rendered much more simultaneous or instan- I taneous, and correspondingly greater and better results are obtained from the dynamite or other explosiveeinployed.

By means of the conical recess the action of the fulminate is extended over a much larger surface, penetrating the body of the compressed body, and giving very nearly simultaneous action to the atonis of gun-cotton.

Having thus described my invention, what I claim is 1. A blasting-cap or detonator consisting of a compressed body of gun-cotton insertedwithin a shell and primed with fnlminate of mercury or other substances, or a mixture of such fulminate withother chemicals, substantially as described.

2. A blasting-cap or detonator consisting of a body of compressed gun-cotton inserted in a copper shell, and having a central recess or chamber formed in the end and extending to- Ward the bottom, and a priming of fulminate JOSEPH R. FRANCE.

Witnesses: 1

J OSEPH B. BRAMAN,

J. CHANDLER BRAMAN. 

